Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['q', '5959', 'I', 'm', 's', 'J', '6439']

17, 5959, 9, 13, 19, 10, 6439